Square Enix's Kingdom Hearts franchise is one of the most beloved long-running series in gaming, and it isn't stopping any time soon. With its fourth mainline title in production, Kingdom Hearts is likely to continue bringing its marriage of Final Fantasy and Disney to fans for years to come. Across over 20 years of releases, however, the lore of the series has probably become some of the most convoluted in gaming.

The complex narrative that has been crafted throughout the many titles under the Kingdom Hearts umbrella can be daunting for new players looking to understand the franchise, but playing the games in order of release can offer a relatively straightforward experience. As its titles have delved deeper into times that predate the mainline games, the timeline of Kingdom Hearts has now explored many events outside the adventures of Sora. As Kingdom Hearts 4 slowly approaches, looking back at the continuity of the series in retrospect can lead players right into the upcoming game.

RELATED: How Strelitzia Went From a Spin-Off to Starring as Kingdom Hearts 4's Quadratum Guide

Kingdom Hearts Union X

A spin-off taking place hundreds of years prior to the events of the first KH, Kingdom Hearts Union X (pronounced "key" or "cross") acts as a prequel that tells of the story of the Master of Masters and his apprentices known as the Foretellers. X Back Cover is a companion animated film set both before and during X, while the updates Unchained X and Union X would go on to continue the narrative into a plot revolving around data worlds and the impending Keyblade War.

Kingdom Hearts Dark Road

The final update to what is now known as Union X Dark Road, this game is notable for featuring series main antagonist Xehanort as its player character. The origin story of the instigator of the events of the Dark Seeker Saga, Kingdom Hearts Dark Road eventually sees a time skip of 64 years that directly leads into Birth by Sleep.

Kingdom Hearts: Birth by Sleep

Possibly the most iconic of the Kingdom Hearts prequels, Birth by Sleep featured the three separate adventures of Terra, Ventus, and Aqua that saw their battle with Master Xehanort lead directly into the events of the original game 10 years later. KH Birth by Sleep - A fragmentary passage chronologically follows right after in a gap-filling lead up to the third game focused purely on Aqua.

Kingdom Hearts

The game that started it all, the original Kingdom Hearts was an innovative experiment of the PS2 era that truly paid off. Seeing the beginning of the story of Sora, Riku, and Kairi, the first game in the franchise introduced the conflict with the Heartless and Darkness as a whole that would continue for years to come.

Kingdom Hearts: 358/2 Days

The spin-off centered on Sora’s Nobody, Roxas, is a somber reflection on one of the boldest concepts of Kingdom Hearts 2 and one of the most emotional experiences of the series for many dedicated fans. Spanning the length between the first and second titles, the context of 358/2 Days’ tragedy is largely unknown to the cast of the mainline games.

Kingdom Hearts: Chain of Memories

A strange fever dream of a story that saw Sora losing his memories in Castle Oblivion, Chain of Memories revisited false versions of Disney worlds while first introducing Organization 13. The story of Marluxia and his failed coup attempt takes place concurrently with 358/2 Days, but all these events were completely forgotten by Sora leading up to the next mainline game.

RELATED: The Kingdom Hearts Franchise Silently Broke a Massive Tradition

Kingdom Hearts 2

Widely considered the peak of the series, Kingdom Hearts 2 improved on many aspects of the original in a bold way. Seeing an older Sora wake up from his rest and return to face off against Organization 13 and its master Xemnas, this game developed the previous cast while also introducing Nobodies.

Kingdom Hearts: Coded

One of the more inconsequential spin-offs, Coded saw a virtual Data-Sora venturing through previously visited worlds once more to stop mysterious “Bugs” in the data worlds. With its entire plot taking place during the end of Kingdom Hearts 2, this game ultimately served to explain the message in a bottle sent by King Mickey.

Kingdom Hearts 3D: Dream Drop Distance

Dream Drop Distance released during the long interim between mainline entries after the second and saw Sora and Riku taking the Mark of Mastery exam through exploring various “Sleeping Worlds”. Setting up the conflict of the third game through the return of Master Xehanort and introduction of his new Organization 13, the young appearances of this game’s protagonists can be misleading.

Kingdom Hearts 3

Finally arriving over 10 years after the previous mainline title, Kingdom Hearts 3 acted as the culmination of all the events of the Dark Seeker Saga that preceded it. With the return of practically every major character from across the series in an epic final battle against every form of Xehanort, all the previous titles were able to factor into this experience. Kingdom Hearts 3: Re Mind would later expand on the game’s bittersweet ending while also setting up the future Lost Master Arc, capping off the majority of the timeline.

Kingdom Hearts Melody of Memory

While a spin-off rhythm game, Melody of Memory is technically the most recent within the series’ timeline. Focused on Kairi as she sleeps for an entire year while searching for clues about Sora’s location in her heart, this game eventually takes place concurrently with Re Mind’s “Limitcut Episode”. Seeing Riku entering the “fictional world” of Quadratum in search of Sora, this game seems to lead directly into the fourth.

Kingdom Hearts 4

Only revealed through a cinematic trailer so far, Kingdom Hearts 4 is set to bring Sora into Quadratum, a world that exists outside of the typical definitions of light and darkness in favor the new concept of “fiction”. The setting of the fourth mainline entry was hinted at through the secret boss Yozora in Re Mind, and will likely somehow relate to the presence of the Masters of Masters and Luxu in the aptly titled Lost Master Arc.

Kingdom Hearts 4 is currently in development.

MORE: Final Fantasy 16's Clive and Joshua are Officially Stronger than Donald Duck